Thursday, April 4, 2013

Yet, Another Blood Clot

I walked into the exam room, not expecting to see or hear what was about to occur.  After knocking on the door, I walked in and introduced myself to the new patient.
“Hi, I’m Sharon, I’m a physician assistant and I’m here helping out for a few months.  How can I help you?”
“Hi, I’m Norma.  This is my husband, Steve.  I came in because I have pain and swelling in my left leg.  It’s just gotten worse over the past week.  Now I can’t walk on it.”
“Hmm, I see.  So have you had any fevers with this?”
“No, but I’ve been sick for the past month at home.  I was running 102 fevers a month ago for almost a week.  I’ve felt so bad for the past month from whatever I had that I haven’t gotten out of bed.  But now with my leg the way it is, I had to come in.”
“Okay.  What other symptoms did you have for the past month?”
“I was totally wiped out, no energy at all.  Didn’t have an appetite, just wanted to sleep all the time, but when I woke up I didn’t feel refreshed at all.  I also had some sinus drainage and a little bit of a sore throat.  But that all was clearing up when my leg started to bother me a week ago, and since then it has just gotten worse.  I’m self-employed, so I was trying to get some work done on my laptop computer at home, but I’ve only been able to do about 3-4 hours each day.”
“Has this ever happened before to you?”
“Yeah, now that you mention it, I had a problem when I was pregnant 25 years ago.  I had a blood clot in this same leg, with pain and swelling.  But it wasn’t this bad, this hurts all the way up to my hip.”

Risk factors for having blood clots include:
--history of immobilization or prolonged hospitalization/bed rest
--recent surgery
--prior episode of venous thromboembolism (blood clot)
--lower extremity trauma
--malignancy (i.e. cancer)
--use of oral contraceptives or hormone replacement therapy
--pregnancy or postpartum status
--history of stroke
--age of > 75 years
--presence of an acute infectious disease
--female sex > male sex

Many physicians use the Wells Score to assess the pretest probability that a patient has a deep vein thrombosis (blood clot).  The patient is given 1 point each for any of the following:
--active cancer
--paralysis, recent immobilization of the lower extremity
--recently bedridden for more than 3 days or major surgery within 4 weeks
--localized tenderness along the distribution of the deep venous system
--entire leg swollen
--calf swelling by more than 3 cms. when compared to the asymptomatic leg
--pitting edema
--collateral superficial veins

Wells Score gives a high probability of a deep venous thrombosis if the patient has 3 or more of the above present.  They have a moderate probability is they have 1-2 of the above, The patient has a low probability of their score is 0. 

“So, tell me what happened 25 years ago?”
“Umm, I think I was about 6 months along when the blood clot showed up.  I had to be in the hospital for a few days while they started me on heparin.  Then when I was discharged, I was sent home on twice daily sub-cutaneous injections of heparin that I had to do until my daughter was delivered, then they stopped the heparin.”
“Did they do any follow-up labs with you to figure out why you had the blood clot?”
“No, they just discontinued the heparin.”
“ Alright, well let me ask you whether you have any drug allergies or take any medications right now?”
“I’m not allergic to anything I know of.  I do take lisinopril for my high blood pressure and fish oil for something to do with my cholesterol?  Is that what you call it, cholesterol?”
“Well, fish oil would be addressing one part of your cholesterol panel, specifically the triglycerides, so yes, you are correct in stating it is for your cholesterol.”
“Well, that’s all I know, what can be done about my leg?”
“We’re going to have to start you back on heparin if indeed you do have another blood clot.  But I also need to quickly listen to your lungs, heart, feel your abdomen, pulses, etc.  Then I’m going to send you over to the hopsital lab for them to draw stat labs on you.”
I proceeded to do her physical exam and with the exception of her left leg everything was normal.  Her left leg had increased heat to it, it was swollen, I couldn’t palpate a dorsalis pedis pulse (the pulse on the top of your foot), nor could I palpate a pulse on the back of her knee.  Her pulse at her hip was decreased at 1+ (normal is 2-3+). 
After I finished up her physical exam, I excused myself from the room and went out to the front desk area and asked one of the office staff to hand me a lab/radiology request form for the hospital.  I quickly filled it out, requesting blood work which included a d-dimer (fibrinogen) and if the d-dimer was positive then they were to do a ultrasound study of her left leg. 

Physical findings for having a blood clot include:
palpable cord (reflecting a thrombosed vein), calf or thigh pain, unilateral swelling of the leg, increased warmth to the affected limb, redness and/or superficial venous dilation. 

Laboratory findings for having a blood clot include: a positive d-dimer (a test for the fibrinogen or clotting factors in the blood)which has to be above 500.  Patients also need to have their total red blood cell count, platelet count (small pieces of blood product that helps form the clot), and coagulation studies (how fast does the patient’s blood clot) done.  They should also have their kidney function tests done as well as a urinalysis.  Then while they are initially on heparin for the first few days they need to have their blood counts re-done daily to make sure that they are not having a problem with the heparin inducing a low platelet count. 

To diagnose how large the clot is (after the d-dimer comes back > 500) an ultrasound doppler study is done.  This assesses the circulatory system of the affected limb and can quantify how large the clot is (where does it start and where does it end). 

An hour later I received a fax from the hospital, the patient’s d-dimer was 4998, dramatically positive.  So I called them back and advised them to proceed with the doppler ultrasound of her leg.  the doppler showed her to have a continuous blood clot from her foot almost up to her hip (from her anterior tibial vein up into her popliteal vein and into her femoral vein.  It did not involve her iliac vein).   With those results,  she was admitted to the hospital and put on IV heparin.  She was kept on this for 5 days at which time she was switched over to daily Xarelto and discharged home to be followed up in the clinic.  She came into the clinic two weeks later and was doing better.  She was now able to walk on her left leg, but with discomfort. 

Treatment for blood clots include:
either in-patient our out-patient treatment with heparin (can be IV or sub-cutaneous injections)
close monitoring of response to make sure the blood clot does not progress
If the patient is going to be switched over to Coumadin then they are on both heparin and Coumadin together, if the patient is going to be switched over to Xarelto then the heparin can be stopped after the first dose of Xarelto (rivaroxaban) has been taken.  There are also two other agents which can be used besides Xarelto and these include dabigatran and apixaban.

Her leg was still swollen, and had some increased heat to it (but not as much as before her admission).  Her pulse at her hip was now more prominent and there was the possibility of her having a pulse at her knee (but that was questionable).  She was followed in the clinic with slow resolution of the large clot in her leg.  At 3 months, the Xarelto was discontinued, she was put back on subcutaneous heparin for two weeks and then had all of her work-up done for her presumed inherited thrombophilia (a predisposition for forming blood clots).

To ascertain the cause of the blood clot it is first determined whether it is a:
--congenital/inherited deficiency (factor V Leiden, protein C deficiency)
--acquired  (following surgery, trauma, antiphopholipid antibody, prenancy)
--associated with systemic disease (cancer, systemic lupus, inflammatory bowel disease).

Once the determination is made that the blood clot is likely inherited then pursuing their abnormal blood clotting factor should be done. 

Patients who have experienced their first blod clot are generally not treated with long term Coumadin beyond 3-6 months.  If the patients have a second episode, they are generally treated long-term (i.e. indefinitely). 

After all of her laboratory work-up was done, she was immediately switched back to daily Xarelto.  Several days later all of her work-up came back and she was positive for Factor V deficiency.  Due to the fact that this was her second episode of having a blood clot, she was continued indefinitely on her daily Xarelto. 

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